The Human Body in Health & Disease – Midterm Study Guide
Detailed Midterm Study Guide – The Human Body in Health & Disease
Levels of Organization
Atom
Smallest unit of matter; forms molecules that build cells.
Cell
Smallest living unit; carries out metabolism, growth, and reproduction.
Tissue
Group of similar cells working together for a function (e.g., muscle contraction).
Organ
Structure made of tissues performing a specific task (e.g., heart pumps blood).
Organ System
Organs working together (e.g., digestive system breaks down food).
Organism
Entire living individual capable of homeostasis.
Anatomical Position, Planes & Cavities
Anatomical Position
Body is upright, feet are forward, arms at sides, palms are facing forward; this position is used as a reference.
Sagittal Plane
Divides the body into left and right sections.
Frontal (Coronal) Plane
Divides the body into front (anterior) and back (posterior) sections.
Transverse Plane
Divides the body into top (superior) and bottom (inferior) sections.
Dorsal Cavity
Protects the nervous system which includes the cranial and spinal cavities.
Ventral Cavity
Houses organs; includes the thoracic cavity and abdominopelvic cavities.
Diaphragm
Muscular sheet used for breathing; separates the thoracic and abdominal cavities.
Chemistry & Cells
Protons
Particles with a positive charge; determine the identity of an element.
Neutrons
Particles with no charge (neutral); function to stabilize the nucleus of an atom.
Electrons
Negatively charged particles involved in chemical bonding; located in electron shells surrounding the nucleus.
Triglyceride
A type of lipid composed of glycerol and three fatty acids; serves to store energy and insulate the body.
Nucleotide
DNA unit made of a sugar, phosphate group, and nitrogen base; serves to store genetic information.
Cell Membrane
A biological membrane that controls what enters and leaves the cell.
Cytoplasm
A jelly-like substance where cellular chemical reactions take place.
Nucleus
Control center of the cell; houses DNA and directs protein synthesis.
Ribosomes and RNA
Ribosomes assemble proteins which are crucial for cell structure and function; RNA plays a key role in the composition of ribosomes.